{
    //ts类型：boolean   
    let bool1:boolean = true

    //number类型
    let num1:number =1

    //string类型
    let str:string='qqq'

    //null和undefined
    let a:null= null
    let b:undefined = undefined

    //bigint
    let num3:bigint = 1n

    //symbol类型
    let sy1:symbol = Symbol()
}